Imagine London, but not the way you know it. Imagine it physically separated, much like Berlin once was, into two zones: one of pleasure and one of practicality. Consider how the city would eventually appear as inhabitants rushed to the pleasure zone; how the zone of practicality would eventually, inevitably become bereft.

This is the London of a young Rem Koolhaas’ imaginings, written for his Thesis at the Architectural Association School in London in the late 60s. Before Delirious New York, before OMA, and much before the CCTV Tower, Koolhaas was inspired by this idea of the divided city – and it’s a fitting image to start thinking about the ever provocative, often controversial Rem: a man who stands with one foot in the world of desire and the other, reluctantly, in that of practicality; a man who would perhaps prefer the title of urban thinker, despite clearly being one of architecture’s great masters.

It’s exactly this in-between-ness, this reluctance to fit into one supposed role, that has been Koolhaas’ greatest asset, that has allowed him to approach the profession from such unlikely angles. Using the city’s freedoms as his inspiration, and rejecting as given the expectations of what architecture is(even questioning its relevance at all), Koolhaas, the “reluctant architect,” is also the most radical of our time, and the most vital for our future.

Despite the contradictions and inconsistencies in Rem Koolhaas’ writings and work, there has always been one constant: his love affair with the city.

For Koolhaas, the city is marvelously random, “chance-like,” crowded, chaotic, liberal. It’s a celebration of life. Delirious New York: A Retroactive Manifesto for Manhattan, published in 1978, was an ode to New York’s beginnings, when the city emerged – not from a rational, Modernist plan – but irrationally, imaginatively, energetically. In describing Mayor Giuliani’s strict efforts to “clean up” New York in the 90s, Koolhaas quipped: “‘Zero tolerance’ is a deadly mantra for a metropolis: What is a city if not a space of maximum license?”

Considering how much Koolhaas values the chaos of a dense city like New York, it stands to reason that he would also have a healthy skepticism of what architects can accomplish; in Delirious New York, he suggested that architects could virtually exert no lasting control over urban life. And its a conviction that’s only strengthened over time.

As Koolhaas is well aware, the last twenty years have been characterized by an explosion of population and urbanization, as cities across the developing world become mega-cities at an unimaginable rate. When he lectures around the world, Koolhaas likes to throw out this fact: in China’s Pearl River Delta, 500 square kilometers of urban substance are created a year. That’s 2 Parises, every year.

In fact, Koolhaas sees places like the Pearl River Delta as the future, choosing not to focus on their poverty, which he accepts as a reality (perhaps due in part to his youth in poverty-stricken Jakarta), but on the opportunities they present. In a fascinating report by OMA on Lagos, Nigeria, they note how ingenuity turns traffic jams into open-air markets, abandoned railroads into walkways, or failed intersections into settlements.

The firm states: “We resist the notion that Lagos represents an African city en route to becoming modern. Rather, we think it possible to argue that it represents an extreme and paradigmatic case study of a city at the forefront of globalizing modernity. This is to say that Lagos is not catching up with us. Rather, we may be catching up with Lagos.”

Despite the problematic denial of Lagos’ significant poverty (read Design Observer’s William Drenttel’s unfavorable take on the matter), the perspective OMA presents here is extraordinary. First of all, it accepts that modernity could actually be a state of spontaneous ingenuities within disorder, rather than a trajectory towards order. Second of all, it suggests that, in the future, the architect won’t really be necessary at all.

In an article for Wired, correspondent Gary Wolf explains Koolhaas’ theory: “In the context of [...] hyperdevelopment, the traditional architectural values – composition, aesthetics, balance – are irrelevant. The speed of international demands is completely out of pace with the ability of traditional designers to respond; construction has left architecture on the sidelines.”

One need only look at the ever-multiplying skyscrapers of China to recognize that Wolf’s statement has indeed come true. Moreover, not only has architecture, as we traditionally conceive it, become too slow to keep up with development, in the end, it’s often unnecessary. Consider the informal settlers of Torre David in Venezuela or the billions of people living in slums, creating vibrant, efficient spaces just as they see fit.

As Koolhaas somewhat famously put it: “People can inhabit anything. And they can be miserable in anything and ecstatic in anything. More and more I think that architecture has nothing to do with it. Of course, that’s both liberating and alarming.”

As polemic as that sounds, you must (as you take anything from Rem Koolhaas) take it with a grain of salt. As much as Koolhaas loves to suggest that architecture is irrelevant, he also admits that the vast majority of thoughtless, “characterless” architecture isn’t helpful either. He describes it as “Junkspace”: architecture which “substitutes accumulation for hierarchy, addition for composition. More and more, more is more. Junkspace is overripe and undernourishing at the same time, a colossal security blanket that covers the earth. … Junkspace is like being condemned to a perpetual Jacuzzi with millions of your best friends.”

If we take as given then that Koolhaas sees a difference between architecture that nourishes and that which undernourishes (Junkspace), and that Junkspace emerges from an unthinking approach to architecture, then, for Koolhaas, what kind of architecture can nourish and, ultimately, resist irrelevance?

As would only be fitting for Koolhaas, the answer lies in the city itself – the vibrant city which lives in a permanent state of flux, of growth and decay. As he explained it: “A few years ago I realized the profession was as if lobotomized – it was stuck conceiving of itself only in terms of adding things and not in terms of taking away or erasing things. The same intelligence for adding ought to also deal with its debris.”

This was the breakthrough of Koolhaas’ career, and the fact that would influence all his future work: that architecture need not be limited to the building of built “solutions,” but rather could be defined as a mindset, a way of approaching the world, of designing for growth and decay.

It’s only with this breakthrough in mind can you begin to resolve the seeming contradictions of Koolhaas: despite being a working architect (and one of its best), Koolhaas’ ultimate goal is to expand the purview of what architecture is,beyond the built. This is why, for Koolhaas, it was necessary to split his focus in two, and form AMO, OMA’s mirror-image and counterpart.

Thus, OMA, despite the innovative nature of its designs, lives in the fairly traditional world of an architecture firm, designing buildings that solveproblems. Indeed, much of Koolhaas’ fame comes from the genius of his buildings’ distinctive organizational responses to the needs of its inhabitants (rather than, like Gehry or Hadid, from a unique style). Take the Seattle Public Library, for example. The building, rather than purely accommodating the future need for new technologies, was structured, in a shockingly logical, book-oriented manner: following the Dewey Decimal system. It was not so much a radical reinvention as a “reinterpretation” of the traditional.

Where OMA’s designs live in the solution-oriented world of the now, it is AMO, Koolhaas’ think-tank of “virtual” architecture, which lives in the future.

AMO utilizes the expansive, analytical eye of the architect, usually wielded to inform the design of a building, as the end in itself. It sells to clients analyses – of human beings, culture, built environments, commerce – and offers solutions. And, most importantly, AMO embraces the possibility that a physical building may not be the solution at all.

To quote Koolhaas again, this idea of built architecture as often unnecessary is both “liberating and alarming” for the architecture profession. Indeed, many of Koolhaas’ critics, who remain firmly in the “alarmed” category, cannot accept a belief that so clearly negates everything architecture has stood for, and often dismiss Koolhaas as a second-rate social critic. However, if you attempt to see the “irrelevance” of architecture as “liberating,” as Koolhaas does, it’s actually an incredibly empowering way of considering architecture’s future, how it should evolve, what it should become.

For all of Koolhaas’ cynical statements and provocations, his is an idealistic vision. For him, “virtual architecture,” perhaps physical, perhaps not, is the future; only the architect’s “expertise in the unbuilt” will be able to match the breakneck pace of urbanization and embrace the possibility of subtraction and decay, the ingenuity and chaos of the city.

Nicolai Ouroussoff once described Koolhaas as “a reluctant architect.” He has good reason to be reluctant; like a city in flux, Koolhaas will keep shifting – from the built to the unbuilt, from practicality to possibility – and keep architecture, in whatever form it may take, alive.